Roy Baumeister

Who they are

The founding study was run at Case Western Reserve University and published in the Journal of Personality and Social Psychology in 1998 by Baumeister, Bratslavsky, Muraven and Tice. Sixty-seven participants were seated at a table holding a stack of cookies and a bowl of radishes; a third were told they could eat only the radishes, and were watched through a one-way mirror to confirm that they did. Everyone was then handed geometry problems with no solutions. The radish group gave up after 8.35 minutes. The students allowed the cookies lasted 18.90, and those who skipped the food stage lasted 19.40. Baumeister and his colleagues called what the radish group had spent ego depletion, and built the strength model of self-control on it: resisting the cookies consumed something that was then unavailable for the puzzle.

Willpower, written with John Tierney in 2011, is where the model left the journals. Two claims travelled with it. The first was that self-control is a finite resource drawn down by use, which is the source of the familiar idea that a day of small decisions leaves you weaker by the evening. The second was that the resource is glucose, restorable with a sugary drink. The advice built on those two claims, making hard decisions early, budgeting willpower across a day, eating before a difficult conversation, all needed the effect to be large.

It was, on the evidence available at the time. A 2010 meta-analysis led by Martin Hagger covering close to 200 experiments put the depletion effect at d = 0.62. What followed is the reason Baumeister appears on this site at all. Evan Carter and Michael McCullough reanalysed that dataset for publication bias in 2014 and found the corrected estimate could be zero; Hagger's own 23-laboratory registered replication returned d = 0.04 in 2016; and a 36-laboratory test led by Kathleen Vohs returned d = 0.06 in 2021.

Baumeister's answer is more substantial than most coverage of it suggests, and it is worth stating in full. In February 2022 he and Tice published an opinion piece in the Scholarly Journal of Psychology and Behavioral Sciences under the title "Ego Depletion is the Best Replicated Finding in All of Social Psychology". They propose four criteria for calling an effect well replicated: many supportive findings across multiple laboratories and methods with few contrary results, at least one preregistered success, a significant multi-site replication, and evidence from outside the laboratory. On the third criterion they point to Dang and colleagues' 12-laboratory replication, which in 2021 did find a small but statistically significant effect of d = 0.10, rising to 0.16 once apparently random responders were excluded. They argue that the two famous nulls should not count against the model. Hagger's protocol, they say, was new and untested, and failed its own manipulation check on fatigue, which would mean the independent variable was never successfully manipulated. One objection concerns the sample used in the Vohs analysis; the replication report sets out the method in full, and both positions are on the record. For the fourth criterion they list field findings, from hand hygiene among clinicians to the timing of parole decisions.

Grant the whole of it and what remains is a real effect of about a tenth of a standard deviation under some conditions. That is not nothing, and it is not what was sold. The drink, the willpower budget and the instruction to make hard decisions early all required the large effect, and none of them survives at d = 0.10.

Key papers

Baumeister, R. F., Bratslavsky, E., Muraven, M., & Tice, D. M. (1998), "Ego depletion: Is the active self a limited resource?," Journal of Personality and Social Psychology, 74(5), 1252-1265. The radish study, N = 67, and the paper that introduced ego depletion and the strength model of self-control.

Baumeister, R. F., & Tierney, J. (2011), Willpower: Rediscovering the Greatest Human Strength, Penguin. The trade book that made the finite-resource account mainstream, including the glucose claim.

Baumeister, R. F., & Tice, D. M. (2022), "Ego depletion is the best replicated finding in all of social psychology," Scholarly Journal of Psychology and Behavioral Sciences, 6(2), 686-688. The defence: four criteria for a well replicated effect, the case for Dang's multi-laboratory result, and specific methodological objections to the Hagger and Vohs replications.

Key ideas

The strength model of self-control: acts of self-control draw on a limited common resource, so exerting control on one task leaves less available for the next.

Ego depletion as the observable consequence, measured in the 1998 study as persistence on an unsolvable task.

The glucose hypothesis, that the resource is metabolic and can be restored with a sugary drink. This is the part of the model that has fared worst.

Four criteria for calling an effect well replicated, proposed in the 2022 defence: convergent findings across laboratories and methods, a preregistered success, a significant multi-site replication, and evidence from the field.

Two methodological objections to the replications, published in 2022, concerning the fatigue check in the Hagger protocol and the sample used in the Vohs analysis; both positions are on the record.

Concepts on this site

Ego Depletion

The Replication Crisis

Self-Compassion

Find them elsewhere

X handle is linked from his own site, roybaumeister.com, and the Scholar profile is verified at uq.edu.au and points back to that same site. No Bluesky or LinkedIn confirmed

Checked 2026-09-10. Handles and affiliations go out of date, so treat this block as a snapshot rather than a standing fact.

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